IOS Programming Tutorials

Mobile development is one of the fastest growing fields in programming. As of 2013, it seems to be the next "gold rush" in programming. And games are at the forefront of it all: games are the most popular category of apps, 93% of purchased applications are games, and 64% of mobile players play every day! [Source  ] Here's our advice to getting started!

Learning Objective-C
First, learn Objective-C, Apple's native language for their devices (Mac and iOS).

Recommended Books:

Programming in Objective-C (5th Edition) by Stephen Kochan

Objective-C Programming: The Big Nerd Ranch Guide By Aaron Hillegass

iOS
Stanford University's iTunes U class is a great video series going over iOS 6 development. https://itunes.apple.com/us/course/coding-together-developing/id593208016

Jimmy Bouker's Tic Tac Toe with Friends: An asynchronous multiplayer game which uses iOS, the Facebook SDK, and the Parse database backend http://bit.ly/16iK5kP

Recommended books:

IOS Programming: The Big Nerd Ranch Guide (3rd Edition) By Joe Conway and Aaron Hillegass

Extra
Apple has an extensive series of videos on everything related to development using their technologies (Freely available to those with an Apple Developer License). https://developer.apple.com/wwdc/videos/